A. Draguhn et al., A SIMPLE HARDWARE MODEL FOR THE DIRECT OBSERVATION OF VOLTAGE-CLAMP PERFORMANCE UNDER REALISTIC CONDITIONS, Journal of neuroscience methods, 78(1-2), 1997, pp. 105-113
A new hardware cell model for electrophysiological recording has been
constructed which allows for the assessment of voltage clamp accuracy
in different recording situations. Each compartment consists of a capa
citor in parallel with a variable resistor and can be connected to oth
er compartments by a variable axial resistance. The simulated membrane
resistance can be changed extrinsically by a command voltage input wh
ich is optically coupled to the cell without any direct galvanic conta
ct. Each compartment possesses a buffer amplifier which reads out the
potential at the simulated membrane element, (e.g. 'somatic' or 'dendr
itic' potential). The model allows for the direct observation of typic
al situations and problems arising in electrophysiological experiments
. We used the model to monitor deviations between the 'intracellular'
and the command voltage, e.g. due to series resistance errors. We also
used the model to simulate synaptic currents which were generated by
triangular membrane conductance changes. The results demonstrate the s
trong influence of synaptic location and series resistance on voltage
clamp fidelity. The cell model is a new and easy-to-handle tool for th
e observation of voltage control under realistic experimental conditio
ns. (C) 1997 Elsevier Science B.V.